Video transcript

What we have here is
a simulation, created by Peter Collingridge
in response to one of our computer
science challenge to show how many particles
might interact gravitationally. And the whole point
of the simulation is to get an intuition
for how galaxies form, why they have the
structures they have, how solar systems form, how they
have the structures they have, and how gravity alone can
kind of define that structure. And what's really interesting
about the simulation, besides the fact that it's just
mesmerizing and extremely cool, is it shows the
particles collide. Once they get to a
certain critical mass, you see that they
get colored yellow, maybe to indicate that
there are now a star. Fusion can now occur. And you can zoom in
at different levels to really see how the
different particles or the different
masses are interacting. And then you can actually
rotate that to see a little bit clearer. This is if I'm looking
kind of right on top of it to see how they're interacting. And it's a three-dimensional
simulation, so it's a very rich way
of thinking about these. And what's exciting
for me is it's highly dependent on what
the initial conditions are. In an earlier version
of Peter's simulation, he did not give a net angular
momentum to the system. And so you did not have as
much of the planet satellite or as much of the disk
structures forming. Although right
here, we don't have too much of a disk structure. Although it does
seem to-- there does seem to be a dominant
plane in this scenario. And what's exciting is here
we have a binary system. Sometimes you restart it. You might not have
a binary system, depending on the
initial conditions. You might have
something that starts to look like the Milky Way. Sometimes you might
have something that looks very different
than the Milky Way. And it really gives
us clues of why we see such diversity,
especially when we're looking at galaxies, the
structure of galaxies, that it's highly dependent
on initial conditions. One can argue that
our own solar system did have some net
initial angular momentum because the current
theory, what really catalyzed it was a nearby supernova
that sent a shock wave and allowed the dust that would
form our solar system to reach a critical mass and
start to condense into the sun and the planets. And so this isn't,
at least in my mind, too unrealistic of a scenario. And it's really cool to
look at, and it really gives you a sense of things. You already see you
have a binary star. They're kind of orbiting
around each other, or orbiting around the center
of mass, which kind of looks like around each other. And then this star
right over here has its own kind
of captive planet that is just rotating around it. We can see it a
little bit clearer. If we had a very, at least from
this perspective, a very close range, we can zoom
in a little bit more to see it a little bit better. This has a satellite,
but then they're are also kind of dancing
around each other. So it's a really
fascinating simulation. I could really stare at this
and play with it for days. I encourage you to play
with it, restart it, see how the initial
conditions or what type of solar systems or galaxies
you might end up with. Whether they form disks, whether
you have binary systems or not, whether you have
planets with satellites. And then if you
are more advanced, actually play with
the code, and see if you can really change
the initial conditions, the starting
velocities of things, the number of
particles of things, the distribution of mass that
you start off with, the angular momentum that you
start off with. And see how that might change
the structure of the universes that you create. And I'm going to add an
annotation to this video that links directly to
this simulation, and I'll also put the link
inside of the description. So have fun. I could literally
spend hours with this. It's a fascinating,
fascinating module that he's created where
you zoom in and out. And I really thank
Peter Collingridge for this incredible
contribution.